Cities grow in two directions — outward and upward. In the process of the condo-ization of downtown, rather like taking old perennials out of a flowerbed and planting new, taller ones, samples of the architecture of the past are disappearing. And so we look both up and back, at five condominium developments that are already up — or soon will be — to discover in words and pictures the buildings that went before them.

RIDEAU CHAPEL / CLARIDGE PLAZA

In the 19th century and well into the 20th, it was perfectly fair to describe Rideau Street as our main street. Visitors from Montreal came in that way, and photographs from the 1860s show it already built up on both sides with dry goods stores and taverns.

In 1869, Rideau Street got a new tenant. The Sisters of Charity located a girls’ school, the Convent of Our Lady of the Sacred Heart, at the corner of Waller. When a new chapel was required 20 years later, the priest, Georges Bouillon, who also happened to be an architect, was engaged and gave the street a quiet place of great beauty. Several generations of young women graduated from Scared Heart before, in 1972, the Sisters sought quieter surroundings and the convent was almost completely demolished, save for the chapel.

The public would not let such beauty disappear, and after a campaign that was anything but quiet, the chapel was carefully dismantled into more than 1,123 separate pieces and warehoused. The National Gallery of Canada later purchased the chapel, and relocation and restoration began in 1984. With a joyful noise, 100 years after its original dedication, the Rideau Chapel was again able to offer its quiet grace to visitors.

Meanwhile, by the time Claridge Homes acquired the site, it had spent 20 years as a utilitarian strip mall of mostly special-interest stores, with a restaurant on the second floor that was famous in the 1980s for its bowls of unshelled peanuts and a choir of waiters who sang “Happy Birthday.” Now, the two towers that form the rampart that is Claridge Plaza make maximum use of the air space that once hovered above the convent. Concrete-clad with a rounded corner at one end and balconies galore on the north side overlooking the bustle of the ByWard Market, they are the latest posts in the fence of condos that is growing along our much-changed main street.